This invention is directed towards a therapeutic treatment for chronic lymphocytic leukemia. The lymphocytes from CLL patients have been found to be sensitive to ultraviolet radiation in the UVC range. It has been found possible to provide a UVC radiation exposure which will kill CLL cells without any measurable adverse effects on healthy lymphocytes taken from non-leukemia control patients. A treatment therapy in which a CLL patient""s blood is treated extracorporeally with UVC radiation is provided which takes advantage of the CLL lymphocyte""s sensitivity to UVC radiation.
Chronic lymphocytic leukemia (CLL) is a hematological malignancy characterized by the clonal expansion of naxc3xafve B-lymphocytes mainly in GO phase of the cell cycle. CLL results in the accumulation of mature immunologically defective lymphocytes in the GO phase. The disease is further characterized by the accumulation of B-lymphocytes in bone marrow, lymph nodes, spleen, and liver. In CLL patients, both the B and T cells are ineffective in their response to antigens and are associated with hypogammaglobulinemia and susceptibility to infectious diseases. The end stages of the disease results in the failure of production of myeloid and erythroid marrow elements as well as the presence of lymphoid masses. It is currently believed that the defective lymphocytes in CLL patients are produced at a normal rate as in healthy individuals, but fail to undergo appropriate apoptosis.
Currently, existing therapies and treatment protocols for advanced clinical stages have met with only partial success. Traditional drug treatments have involved combinations of chlorambucil (an alkylating agent) and prednisone (corticoid steroid). More recently, the purine analog fludarabine has been shown to have positive effects on new and pre-treated CLL patients. However, such drug treatments pose undesirable side effect for some patients. Further, some patients develop resistance to a particular drug.
The use of UVA radiation in an extracorporeal photo chemotherapy has been tested in CLL patients and has brought about improvements in T-cell lymphoma patients, but showed no clinical effect in CLL patients. (Wieselthier, J. S. et al Inefficacy of Extracorporeal Phytochemotherapy in the Treatment of T-cell Chronic Lymphocytic Leukemia: Preliminary Results. American Journal of Hematology, 41, 123-127 (1992) and (Edelson, R. L. xe2x80x9cPhotopheresis: A Clinically Relevant Immunobiologic Response Modifierxe2x80x9d ANN NY Sciences, Vol. 636 p. 154-164 (1991)) and which are both incorporated herein by reference.
Accordingly, there remains room for variation and improvements with respect to therapies and treatments for CLL.
It has now been discovered that a therapeutic treatment to CLL patients may offer improved efficiencies in alleviating symptoms and offer a useful therapeutic tool in minimizing the onset and severity of symptoms. In so doing, it is possible to avoid chemical drug treatments which may have adverse effects and for which the body may develop resistance
In one aspect, the invention resides in a method of treating lymphcytes of CLL patients so as to preclude population accumulation of naxc3xafve B-lymphcytes. The use of UVC radiation of the affected population of lymphocytic cells has been found to bring about the cell death of the targeted population of cells through a combination of apoptosis and cell necrosis. In yet another aspect of this invention, it has been found that the levels of UVC radiation needed to bring about the death of the target population of lymphocytic cells is approximately 10% the level required to bring about deleterious effects on healthy lymphocytic cells.
In a further aspect, the present invention resides in a process of treating a CLL patient by removing a portion of a patient""s blood supply; separating the blood supply into a fraction enriched with lymphocytes; exposing the lymphocyte-enriched fraction to UVC radiation; and, returning the treated fraction and untreated fractions to the patient.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims.